Method of producing glossy surfaces on printed work and products thereof



Patented Mar. 8,- 1938 UNITED STATES METHOD OF PRODUCING GLOSSY SUR- FACES ON PRINTED WORK AND PROD- UCTS THEREOF Hans Schaefer, Frankforbon-the-Main, Germany, assignor to Atlas-Ago, Chemische' Fabrik, Aktiengesellschaft, Molkan, near Leipzig, Germany,.a corporation of Germany No Drawing. Application March 12, 1936, Se-

rial No. 68,446.

8 Claims.

The present invention relates to the art of finishing paper surfaces, and, more particularly, to an improved method of producing glossy effects on the surface of printed work on paper and similar sheet-like materials, used in advertising and illustrating.

Heretofore, if it was desired to .obtain glossy effects on the surface of paper sheets and similar sheet-like materials, the surface was coated with a lacquer of glossy character the coating being provided by brushing, dipping, spraying and similar operations. These conventional methods were very unsatisfactory because the product was unattractive and cheap in appearance. Moreover, the coating of lacquer provided by means of the conventional operations was relatively thick and imparted rigidity and stiffness to the coated paper surface so that 'it lost most of its resiliency, flexibility, pliability and strength. Frequently, the coating of lacquer broke, split and disintegrated from the coated surface by even slight bending or deformation of the paper base. It has already been suggested to incorculty and the finished sheets could not be piled on topof each other. The'problem has engaged the attention of those skilled in the art for a considerable length of time and numerous suggestions and proposals have been made to solve the outstanding problem. However, as far as I am aware, none of these various suggestions and proposals has been completely satisfactory and suc? cessful when reduced to practice on a commercial and industrial scale.

practical solution of the outstanding problem.

It is an object of the present invention to provide a novel and improved method of preparing 'glossy surfaces on paper and generally on the surface of printed work, which is simple and inexpensive, and which is free from the disadvantages and shortcomings of conventional coating methods. l

It is another object of the present invention to provide .a novel method of treating the surface of gloss thereto which does not destroy'the elasticity of the\treated sheet and which will not deteriorate, break or flake off when the sheet is bent or deformed.

I have discovered a remarkably simple and In Germany March 12, 1935 It is a further object of the invention to provide durable and attractive lacquer coatings on the surface of sheet-like materials and of printed work which coatings have a greatly reduced thickness and which will strongly and permanently adhere to the base.

The invention also contemplates :a printed sheet-like product of novel character having a highly attractive glossy surface which may be readilymanufactured at a low price on a mass production scale for the purposes of illustrations and advertising.

Other and further objects and advantages of the invention will become apparent from the following description.

Generally speaking, according to the principles of my invention I prepare a printed work, such as a picture having a conventional dullilnish by any of the conventional printing processes.

On this base, I provide an extremely thin layer or coating of a suitable lacquer by means of 1 printing with a printing roller on which a screen of densely arranged fine lines is engraved or etched. I prefer to use a lacquer of quick drying character which, in View of the extremely 'thin character of the printed coating, will dry almost instantaneously and will impart to the treated surface an attractive glossy appearance which is free from the unattractive, clumsy and cheap effects of the conventional lacquered products produced by means of brush, dipping or spraying. Moreover, my novel and improved lacquer coating provided by means 'of the screenroller, is so thin and is so firmly and resiliently bonded to the base that breaking, flaking or other deterioration of the lacquer is practically impossible. I a

In practical operation, I preferto use cellulose ester lacquers, for example a lacquer of nitrocellulose ester base. I have found that in order to obtain a strong and uniform lacquer coating, it is desirable to use a screen having a relatively great line density, preferably about 48 to about '70 lines per square centimeter. These limits are V preferred. When the line density is excessively high, there-is danger that the roller does not take up sufllcient quantities of the lacquer. On the other hand, when line densities or screens similar to the ones used in ordinary printing practice are employed, the coating of lacquer does not cover uniformly the base. The depth of the screen or the. lines is preferably greater than that of conventional reproducing processes but not so deep that the furrows are destroyed or deformed.

ing and for the coating process, respectively, are

parallel the finished product will display a'peculiar effect, similar to the wellknown moireeffect, in that the outlines of the picture become indistinct. This is the more remarkable, because the screen lines of the coating are hardly or not visible at all on the finished'product with the unaided eye.

For the coating of lacquer, I prefer to use. a cellulose ester lacquer, particularly a lacquer having a nitro-cellulose base. By using these lacquers, no softening agents are necessary so that the coating on the finished product is completely dry, non-sticking and odorless.

For the purpose of giving those skilled'in the art a better understanding of the invention, the following illustrative example is given:-- v

By means of intaglio printing with a screen of about 70 a picture is printed. The finished print is provided,with a fine coating of nitrocellulose lacquer by means of a screen-roller arranged in the same printing machine. The screen or coating roller is made of electrolytic copper having a circumferential surface which has been subjected to strong etching with an iron chloride solution of about 39 B. at. a temperature of about 18 to about 20 C. for about twenty minutes. A thin-flowing nitrocellulose lacquer coating is printed on. the picture by means of the screen roller prepared in the described manner.

,In' another case, a four color picture was printed by means of a four color book printing process by means of a screen-autotype. The coating of lacquer has been provided by means of an intaglio roller which had a screen' of 70 lines etched therein and which served for carrying over th tive and cheap appearance of conventional laclacquer to the picture.

The depth of the screen on the roller may be controlled by adjusting the time of the etching. Generally speaking," the etching must not be carried so far as to attack the so-called screen furrows". In'some cases, it is possible to reduce the etching time by using coarser screens, although this may cause the surface of the lacquer not to adhere as smoothly to the treated surface as with the screens of 60; or 70. Of course, the present process may be applied to printed work of all kinds including prints on metal 'foils and similar materials.

It is to be noted that the process of the present invention provides important advantages. First of all, a novel and attractive glossy, printed product is provided which is inexpensive and which is very suitable for the purposes of illustrations and advertising. The finished product is strong and durable, immediately dry and non-sticking so that the product is easily handled and may be used for example in books.

It isalso to be observed that the glossy effect is of an entirely novel character and immediately attracts attention without having the unattracquered pictures.

Moreover. the process of the invention has the great advantage that the coating of lacquer is extremely thin and'has only a fraction of the thickness'of conventional lacquer coatings provided by means of brushing, dipping or spraying. Thus, substantial savings may be effected in the amount of lacquer necessary, and, in addition, the extremely thin coating of the invention will dry almost instantaneously so that the manufacturing process may be carried out at high speeds in a simple and efflcient manner. This circumstance is of especial importance when the process is carried out on a mass production scale for printing advertising matter and the like.

Although the present invention has been described in connection with a preferred embodiment thereof, variations and modifications may be resorted to by those skilled in the art without departing from the principles of my invention. 1 consider all of these variations and modifications as within the true spirit and scope of the present invention as disclosed in the present specification and defined by the appended claims.

I claim:

1. As a new article of manufacture, a highly glossy printed product comprising a base, a conventional print on the surface of said base, and a screen constituted of fine lines of lacquer devoid of pictorial designs printed onto the surface of said conventional print and forming a highly glossy coating thereon.

2. As a new article of manufacture, a highly glossy printed product comprising a base, a conventional print on the surface of said base, and a screen constituted of fine lines of cellulose ester lacquer devoid of pictorial designs printed onto the surface of said conventional print and forming a highly glossy coating thereon.v

3. As a new article of manufacture, a highly vertising, and the like which comprises preparing a conventional print on a sheet-like material,

and subsequently printing with a lacquer solution onto the surface of said conventional print a screen constituted of a plurality of uniformly arranged fine lines devoid of pictorial designs whereby a highly glossy finish will be imparted to the surface of said print.

5. The method of producing highly glossy pic'- torial prints for the purposes of illustrations, a'dvertising, and the like which comprises preparing a conventional print on a sheet-like material, and subsequently printing with the solution of a cellulose ester lacquer onto the surface of said conventional print a screen constituted of a plurality of uniformly arranged fine lines devoid of pictorial designs whereby a highly glossy finish will be imparted to the surface of said print.

6. The method of producing highly glossy pictorial prints for the purposes of illustrations, advertising, and the like which comprises preparing a conventional print having a substantially dull rality of uniformly arranged fine lines devoid of pictorial designs, the number of said lines not exceeding about 70 per square centimeter whereby a highly glossy finish will be imparted to the surface of said print.

7. The method of producing highly glossy pictorial prints for the purpose of illustrations, advertising, and the like vwhich comprises preparing a. conventional print on a smooth surface, and subsequently printing with a nitrocellulose lacquer solution onto the surface of said conventional print a screen constituted of a plurality of uniformly arranged fine lines devoid of pictorial designs, said screen having a line density of about 48 to about 70 lines per square centimeter whereby a highly glossy finish will be imparted to the surface of said print.

8. The method of producing highly glossy multi-color pictorial prints for the purpose of illustrations, advertising and the like which comprises preparing a conventional multi-color print by means of a screen process, and subsequently printing with a lacquer solution onto the surface of said multi-color print a screen constituted of a plurality of uniformly arranged fine lines devoid of pictorialdesigns, the lines of said multi-color printing screen and of said lacquer printing screen being arranged at different angles whereby a highly glossy finish will be imparted to'the surface of said multi-color print.

HANS SCHAEFEI-t. 

